Various types of prefabricated construction have hitherto been proposed such as modular units, prefabricated trusses and deck panels.
In one prior art prefabrication method, such as described in U.S. Pat. No. 3,555,763 issued Jan. 19, 1971 to David E. Bloxom, panels are formed by:
(a) preparing a plurality of outer metallic skeletal panel frames, each being prepared by joining metallic channels at the periphery of the panel frames, bowing the channels in at the center of the sides to effect a dimension in width at the center less than the width at the top and bottom of the panel frames, and affixing metal reinforcing bars between opposite channel sides of the panel frame PA1 (b) placing the skeletal panel frame on a bed and pouring a lightweight concrete slurry within the panel frame to produce a prefabricated panel having the metallic channel at its periphery; and PA1 (c) positioning the panels on a foundation and joining the metallic channels.
The obvious disadvantages of this known prefabrication panel are that an improper bowing can not be corrected once the concrete has been poured, which may result in loss of both time and materials, and that inward (concavity) bowing of support channels inherently results in a weaker panel and structure. This condition will exist in particular where a door or similar opening is provided within such a panel in that the diminished concrete portions of the panel about the opening may crack and be unable to withstand the inward stress from further bowing of the channels under the weight of the structure.
The present invention involves a novel combination of features combined in such a way as to afford a very efficient, cost effective solution to the difficulties and problems encountered with the prior art, as will become apparent as the description proceeds.
For example, in contrast to the prior art, the present invention provides a method of forming prefabricated panels whereby their opposite support channels may be adjustably constrained during fabrication to provide a substantially parallelogram shaped wall panel. In this manner, the vertical support channels are caused to maintain a substantially straight and parallel disposition to facilitate wall construction and strength. A further feature of the present invention is the provision of a plurality of hook means affixed to the side channels and extending into the concrete for holding the channels in their straight and generally parallel orientation about the hardened concrete. Another feature which may be utilized is a re-usable height adjustable concrete joint edge forming plate which is bolted onto the channels and extends upwardly to form a ledge retainer for the concrete slurry.